Packing material unit

ABSTRACT

A packing material unit for liquid-gas contact apparatus which is essentially six to 12 turns of a helix arranged about a circle and having the ends joined to form a torus. The helix comprises a filamentous material, and each loop of the helix is preferably or substantially circular. The loops carry one or more sharply defined surface interruptions in the form of abrupt nicks or projections, and preferably knobs and notches on exposed surfaces of the torus.

United States Patent [191 Doyne [451 Aug. 14, 1973 PACKING MATERIAL UNIT[75] Inventor: Richard F. Doyne, Summit, Ohio [73] Assignee: TheCellcote Company, Inc., Berea,

Ohio

[22] Filed: Feb. 19, 1971 [21] Appl. No.: 117,028

[52] 11.8. CI. 261/94, 261/112 [51] Int. Cl B011 3/04 [58] Field ofSearch 261/94, 95, 98, 112

[56] References Cited UNITED STATES PATENTS 1,480,463 1] 1924 Petzel261/95 1,796,501 3/1931 Berl 261/94 2,602,651 7/1952 Cannon". 261/952,867,425 l/l959 Teller 261/95 2,949,934 8/1960 Schrenk 261/95 3,167,600H1965 Woman 261/94 3,266,787 8/1966 Eckert 261/94 3,618,910 11/1971Arndt 261/94 FOREIGN PATENTS OR APPLICATIONS 93,843 3/1923 Austria261/94 229,999 l/l9ll Germany 261/95 768,316 2/1957 Great Britain.....261/94 1,029,346 5/1958 Germany 261/94 OTHER PUBLICATIONS Maspac TowerPacking Bulletin, Saran Lined Pipe Co., Ferndale, Mich., 261-295,7-26-66, pp. l-7.

Primary Examiner-Tim R. Miles Attorney-Meyer, Tilberry 8L Body [57]ABSTRACT- A packing material unit for liquid-gas contact apparatus whichis essentially six to 12 tums' of a helix arranged about a circle andhaving the ends joined to form a torus. The'helix comprises afilamentous material, and each loop of the helix is preferably orsubstantially circular. The loops carry one or more sharply definedsurface interruptions in the form of abrupt nicks or projections, andpreferably knobs and notches on exposed surfaces of the toms.

19 Claims, 12 Drawing Figures PATENIEDMM mu m 1 of 2 3.752.453

\3 I INVENTOR. RICHARD F. DOYNE BY 777% W r 60% ATTORNEYS.

PAIENIEUAUBMIQH 3.752.453

SHEEI 2 0F 2 INVENTOR. RICHARD-E DOYNE ATTORNEYS.

I used in air pollution control equipment, gas and liquid contactapparatus for absorption or desorption of gas, rectification columns,mist and entrainment separation of solid and liquid particulates, andthe like.

These packing materials are known in various sizes and shapes, usuallydesigned to bring two phases of a system, typically a gas or mist and aliquid, into intimate contact. Packing materials of a filamentous formare disclosed in the Teller US. Pat. No. 2,867,425, issued Jan. 6, 1959.Other packing configurations heretofore known are berl saddles andRaschig rings.

Packing materials work either by presenting an extended thin film of onephase, usually the liquid, to the other phaseor by constantly renewingthe surface of one phase, usually the liquid, so that the most efficientmass transfer between phases can occur with the least expediture ofenergy. In either case, however, the number of intersitial holdup pointsprovided per cubic foot of packing is extremely important. These arepoints where the surface of one phase, usually the liquid, is renewed byagglomeration and redispersion, to provide a fresh unsaturated surfaceto the other phase. The other governing factor is the surface area ofthe packing.

Interstitial holdup points are provided both by the shape of the packingand by its intersections with the packing immediately surrounding it.Thus it is true that interlocking, by increasing the number of contactpoints between packing units, increases the number of interstitialholdup points, and this fact makes interlocking of packing units lessobjectionable than it was formerly considered, but interlocking stillhas disadvantages. Among these are the tendency interlocking has toblock fluid flow and thus increase the pressure drop through the packedspace, and the fact that extensiveinterlocking requires more packingunits per cubic foot, which increases the weight and cost of largeinstallations.

Interlocking can be prevented, and of course such prevention normallyhas the effect of reducing the number of interstitial holdup points.Thus, prevention of interlockingmay not be desirable. What is needed isa packing unit which provides for reducing interlocking and at the sametime advantageously provides a large number of interstitial holduppoints, whereby reliance for such holdup points on contact with otherpacking units by interlocking is lessened. Such a packing unit wouldhave the inherent capacity to provide better phase surface regenerationwithout being interlocked with other packing units, and wouldsimultaneously require less pressure drop through the packed space,while increasing efficiency.

It is accordingly an object of this invention to provide a packing unitfor liquid-gas contact apparatus by which more efficient operation ofthe apparatus is achieved while using fewer packing units per cubicfoot.

Another object of the invention is to provide a packing material unitwhich provides for less interlocking with other packing units so as torequire fewer units per cubic foot while simultaneously providing withineach packing unit an increase in contact between the gas and liquidphases passing through the equipment.

A further object of this invention is to provide more interstitialholdup points, and thus better phase surface regeneration, in anindividual piece of packing, thus reducing dependency on packing unitcontact with surrounding or interlocked pieces of packing toachieve suchholdup points.

Still another object of the invention is a packing unit which providesmaximum time for mass transfer between the liquid phase on the one handand the gas or mist phase on the other, by increasing within the unititself the number of points of surface regeneration, which involvesagglomeration and dispersion.

Yet another object of the invention is a packing unit which provides alonger retention time of the liquid phase passing through a liquid-gascontact apparatus while reducing the pressure drop in the gas phasethrough the apparatus.

By the present invention, a surface or surfaces of a packing unit areprovided with sharply contoured projections or recesses which defineabrupt interruptions to liquid flow along the surface and which reduceinterlock-ing between adjacent units.

Such projections and recesses can be of any number of differentstructural configurations designed to achieve rapid breaking up ofliquid flow contacting the projection or recess either as a result ofimpact therewith by dropping from a unit thereabove or by contacttherewith during flow along the packing unit surface. For example, theprojections can be cylindrical, square,

rectangular, triangular, oval or diamond shaped in cross section. It isnecessary that the projections or-re-.

cesses define abrupt changes in the surface contour to cause immediatesplitting or breaking of liquid impinging thereagainst to facilitaterepid surface regeneration. Such splitting or breaking of liquid is tobe clearly distinguished from unit surface configurations designedsimply to increase surface area and spread or guide liquid flow relativeto the surface. The concept of the present invention, is distinctivelycharacterized by providing for more holdup points and at the same timemore positive breaking of liquid flow whereby acceleration of surfaceregeneration is achieved and without the degree of interlockingheretofore required to achieve the number of holdup points.

Although applicable to any of the known packing unit configurations,such as the berl saddles and Raschig rings mentioned hereinabove, theinvention is described herein in conjunction with a filamentous packingunit. Such a filamentous packing unit may be provided in any suitableconfiguration and is described herein in a preferred form which is atorus having six to twelve loops defined by a helix extending about aninner circle and having the free ends of the loops joined together. Itwill be appreciated too that the specific helix configuration describedhereinafter is but one of many configurations of looped filamentousmaterial which could be designed without departing from the basicconfiguration of a plurality of loops oriented about a central axis.

.In the preferred packing unit configuration, each loop of the helix isa filament forming a substantially closed loop having a basic geometricconfiguration which is altered by abrupt projections and/or recesses inthe configuration which effectively impede nesting or interlocking ofpacking units and define the holdup points thereof. In some units, anouter peripheral ring or rings extend about the torus each defining aclosed loop of a filament and which closed loop or loops in turn may beprovided with abrupt projections and/or recesses. The abrupt changes inthe surface contour of the filaments of the preferred embodimentadvantagcously lend to the manufacture of a packing unit with thinner,more closely spaced filaments. In this respect, thinner filamentsprovide smaller targets for the inertial impactment of liquid or solidparticulates from an airstream. A multitude of small targets are wellestablished as providing better efficiencies in particulate removal. Thepreferred embodiment of this invention allows the interstitial orsurface renewal points to be maintained for maximum gas absorption ordesorption, while obtaining good efficiencies in particulate removal aswell. Moreover, by reducing interlocking and compacting of the units, areduction in pressure drop through a body of packing units isadvantageously achieved.

The invention may take physical form in certain parts and arrangementsof parts, preferred embodiments of which will be described in detail inthis specification and illustrated in the accompanying drawings whichform a part hereof and wherein:

FIG. 1 is a top plan view of a packing unit made according to thisinvention.

FIG. 2 is a side elevation view of the packing unit shown in FIG. 1.

FIG. 3 is a view in section substantially on line 3-3 of FIG. 1.

FIG. 4 is a view similar to that of FIG. 1 but showing anotherembodiment of the invention.

FIG. 5 is a side elevation view of the embodiment shown in FIG. 4.

FIG. 6 is a view similar to FIGS. 1 and 4 but showing stillanotherembodiment of the invention.

FIG. 7 is a side elevation view of the embodiment shown in FIG. 6.

FIGS. 8, 9 and 10 are views similar to that of FIG. 3 but showing otherforms and shapes which the individual loops of the torus may take indiffering embodiments of the invention.

FIG. 11 is a side elevation of yet another form of an individual loopwithin the present invention.

FIG. 12 is a plan view of the loop shown in FIG. 11.

The packing units of the preferred embodiment of the present inventionherein described are preferably produced from a material which is notwetted by the liquid employed in the system. Accordingly, many plasticmaterials are suitable for use in making the packing units. Preferably,polyethylene is employed. Polypropylene, polyvinyl chloride, chlorinatedpolyvinyl chloride, nylon, fluorocarbons and polystyrene are alsosuitable materials. Further, although plastic materials are preferable,metlas can be employed to produce packing units.

The superior performance of packing units within the present inventionis illustrated by the results of tests in which packing units of thecharacter illustrated in FIG. 1 of the drawing were compared with thesame size packing units, but not having the projections of applicantsunits thereon. In the tests of each type unit, packing units wereintroduced into a packing container portion of a countercurrent PilotScrubber. Tests were run employing four rates of liquid flow and a widerange of gas flow rates for each liquid flow rate. More specifically,gas flow rates of from 500 Ibs./hr./sq. ft. to 2,300 lbs./hr./sq. ft.were employed in conjunction with each of four liquid rates of 1,500,2,500, 4,000 and 6,000 lbs./hr./sq. ft. Scrubbing liquid was used on aonce-through basis and maintained at 77F. The gas flow was ammonia-airand inlet and outlet concentrations were determined by wet chemicalanalysis. The results ofthe several tests disclose that: 1.) 25 percentless packing units with projections are required per cubic foot ofpacking space; (2.) A reduction of up to 30 percent in pressure drop isachieved using packing units with projections; (3.) Efficiency for bothunits under the same operating conditions is substantially the same,whereby the efficiency of a single packing unit with projections isapproximately 25 percent greater than that of a unit withoutprojections.

The results of the above tests demonstrate that considerable savings inthe capital cost and the cost of operation of a packed separation unitcan be readily achieved employing applicants packing unit. In thisrespect, approximately 25 percent fewer units per cubic foot arerequired and the gas fan horsepower can be decreased in view of thelower pressure drop through the unit, all while achieving the same highlevel of efficiency previously obtainable.

The above benefits are derived by providing for the individual packingunits to have sharply defined deviations from the surface conoursthereof, which deviations function both to increase the number of holdupor drip-off points on the unit itself and reduce the amount ofinterlocking with an adjacent unit. Thus, in a given mass of such units,fluid flowing therethrough, influenced by gravity only and not by forcedflow, impinges against an abrupt projection or recess and is immediatelybroken or diverted to leave one unit surface and drop to another surfaceof the one unit or a surface of another unit. Thus, rapid surfaceregeneration is advantageously realized. Moreover, the reduction ininterlocking provides a less compact mass and thus desirably providesfor less pressure drop of gas passed through the mass. Finally, theincrease in holdup or drop-off points per unit together with thedecrease in interlocking provide for separation apparatus operation withfewer packing units per cubic foot and at an efficiency equal toapparatus employing 25 percent more packing units of the same nominalsize. When it is considered that 1,000 units of nominal 1 inch sizewithout projections are required to fill one cubic foot of packingspace, the savings realized by use of applicant's packing unit must beappreciated.

Referring now to the drawings in greater detail wherein the showings arefor the purpose of illustrating the preferred embodiments of theinvention only and not for the purposes of limiting the same, FIGS. 1, 2and 3 show a plurality of filament portions 10 each of which issubstantially in the form of a loop having a basic geometricconfiguration, such as a circle. Preferably, six to 12 loops 10 arearranged about a central imaginary circle to form a figure which closelyresembles a torus. More particularly, in a preferred embodiment of theinvention, each of the filament portions 10 is a loop of a helix, theends being joined together in areas 11 to form a continuous helix whichgives the overall packing unit the appearance of a torus. In FIGS. 1, 2and 3, the basic filament portions 10 have inner and outer peripheralsurfaces 12 and 13, respectively, as well as opposed side surfaces 14.All of these surfaces have opposite ends meeting in areas 11 and each ofthe surfaces defines a flow path for liquid. The extent to which flowalong any one of these surfaces is realized is, of course, dependent onthe orientation of a given unit in a mass of units. One or more ofsurfaces 12, 13

and 14 is provided with at least one deliberate abrupt interruptiondisposed along the surface intermediate the opposite ends thereof, suchas, for example, the substantially cylindrical projections 15 andrectangular projections 16. Preferably, projections 15 are positionedboth on the inner peripheral surface 12 and outer peripheral surface 13of each loop and it will be noted that both projections and 16 havecorresponding wall portions 15a and 16a extending substantiallyperpendicular to the corresponding surface of the loop. A sharplydefined junction is thus provided between the loop and projections. Theabrupt interruption of the contour of surfaces 12 and 13 defined by theprojections and corresponding loop surface has a distinct advantage overa large radius domed embossment or wave in the surface. In this respect,a droplet of water or other liquid flowing along a surface of a loop 10toward a projection 15 or 16, or directly impacting against a projection15 or 16 upon falling from a unit thereabove, will contact theprojection and immediately be broken and given a new and abruptlydifferent direction of flow relative to the initial direction of flow,rather than merely passing over or around the interruption if it were inthe form of a wave or domed embossment.

Although projections 15 are illustrated in FIGS. 1, 2 and 3 ,to bedisposed only at the upper and lower extremities ofa loop 10 ofahorizontally oriented packing unit and on inner and outer surfaces 12and 13 of the loop, it will be appreciated that any number ofprojections may be positioned along the entire periphery of a given loopor loops of the unit and along the inside and/or the outside surface ofthe loop. Moreover, the projections may be plaed along the side surfacesof the loops.

It will be noted that the diameter of cylindrical projections 15 issubstantially the same as the width of-the corresponding loop surface.This assures that liquid flow along the loop surface will be broken andthe liquid caused to leave the corresponding surface rather thanto flowaround the projection and rejoin on the other side thereof. Thisprovides for more rapid surface regeneration by displacing the liquidfrom the original surface along which it was flowing.

The projections 16, mentioned above, are illustrated as beingrectangular projections disposed at the radially outer extremities ofloops 10 of a horizontally oriented packing unit. Projections 16, likeprojections 15, have sharply defined junctures with loops 10. In thisembodiment of projections, the sides 16b of the projections extendbeyond the corresponding side surfaces 14 of loops 10, whereby liquidflow along the outer surface of a loop 10 and around correspondingprojection 16 and back onto the outer surface of the loop is prevented.It will be appreciated that rectangular projections 16 are anotherpreferred form of projections which can be used with loops 10 eitheralone in the position illustrated, or in combination with projections15. Moreover projections 16 can be used in place of cylindricalprojections 15. Again, as with projections 15, projections 16 defineabrupt changes in the surface contour which tend to break liquid flow'to increase surface regeneration and at the same time serve to reduceinterlocking of adjacent packing units. It will be further appreciatedthat projections 16 could function equally as well for these purposes ifthey were of a width substantially equal to the width of surface 13 ofthe loops.

As illustrated in FIGS. 4 and 5 of the drawing, a peripheral ring 17 maybe provided about the packing unit loops. It will be noted in thisembodiment that filament portions 10a are defined by a continuousfilament which is helically wound to define the loops. Ring 17 is eitherintegral with or is otherwise suitably connected to some or all of theloops, has wall portions 17a substantially perpendicular to the outersurfaces of the loops and defines for each loop a sharp interruption inthe surface contour thereof. Thus ring 17 serves to 'break liquid flowin a manner similar to projections 15 and 16 and it will be readilyappreciated that the ring greatly lessens interlocking of adjacentunits. A similar ring could be disposed within the inner circle definedby the torus, alone or in combination with ring 17. Moreover, a ring orrings could be disposed within the annular space defined by the innersurfaces of the loops. Many modifications of the use of such a ring willbe apparent from the foregoing description. Preferably, ring 17 or anyother ring or combination of rings employed with the packing unit, isprovided with projection means 18 which may be similar to and is for thesame purpose as projections 15 and 16 described here-' inabove.Moreover, filament portions 10a may be provided with projections 15astructurally similar to projections 15.

FIGS. 6 and 7 of the drawing illustrate a further embodiment of the useof a ring component with the packing unit similar to the unit in FIG. 1.In this instance a ring 19 is disposed about the top of the unit and isintegrally or otherwise secured to projections 20 extending upwardlyfrom the outer surfaces of the upper extremities of loops 10b which, inthis embodiment are defined by a continuous helically wound filament.Projections 20 are similar to projections 15 and 16 describedhereinabove. It will be appreciated that this disposition of a ringrelative to the loops of the unit greatly lessens interlocking ofadjacent units. Projectionsmay be provided on the several surfaces ofring 19 similar to and for the same purpose as the projections 15 and 16hereinbefore described. Further, projections 21 similar to projections16 may be provided on loops 10b, as illustrated, or a ring similar toring 17 could be provided to circumscribe the loops.

FIG. 8 illustrates a further embodiment of the present invention and, inthis respect, discloses a loop of the basic packing unit provided withsharply defined recesses 22 which abruptly interrupt the surface contourof the loop to define interruptions to liquid flow along thecorresponding loop surface to achieve immediate breaking of flow andrapid surface regeneration. The recesses 22 may be provided in both theinner and outer surfaces of the loop, as illustrated in FIG. 8, or maybe provided on either surface alone. Moreover, it will be appreciatedthat the recesses amy be provided in one or both of the side surfaces ofthe loops, and in any number desired along the lengths of the inner,

outer and side surfaces. Still further, it will be appreciated thatrecesses of the character of recesses 21 may be employed in conjunctionwith any of the projections hereinbefore described and in any desiredcombination therewith. It will be noted too that the recesses aredefined by walls 22a extending substantially perpendicular to the loopsurfaces and that sharp edges are defined at the points of intersectionof walls 22a with the corresponding loop surface. These sharply definedcontours, as with the projections previously described, define sharp orabrupt deviations in the loop surface which enhance breaking liquid flowalong the surface to achieve rapid surface regeneration and at the sametime serve to deter interlocking.

With reference now in particular to loops 10, 10a and 10b of FIGS. 3,and 7, respectively, each loop is a filament portion which incross-section, in the preferred embodiment, is rectangular orsubstantially square. Each filament portion is substantially a loophaving a basic circular configuration. These loops are considered to besubstantially closed because of the junction in areas 11 of loops l0 andthe close proximity of the radially inner ends ofloops a and [0b. InFIGS. 9 and 10, however, gaps 23 and 24 are provided, respectively inloops 10d and 10e. For the purposes of the present invention, the loopsshown in FIGS. 9 and 10 are substantially closed loops because the gaps23 and 24 are not wide enough to permit passage through the gap of afilament of an adjacent packing unit, and thus the gaps cannotcontribute to interlocking of adjacent packing units. Additionally, thelocation of the gap 23 in the loop 10d in FIG. 9 immediately adjacent tothe point of attachment 25, by which the loop is secured to its adjacentloop, also contribures to the inability of gap 23 to permit interlockingof adjacent packing units. For that reason, the gap 23 shown in FIG. 9could be wider than the gap 24 of FIG. 10 without permittinginterlocking of adjacent packing units.

Each of the filament portions is a loop having a basic geometricconfiguration, as mentioned above. Thus, the filament portions shown inFIGS. 3, 8 and 9 are basically circles, while the filament portion ofthe embodiment shown in FIG. 10 is a substantially closed loop having abasic geometric configuration which is a hexagon. The filaments of thesebasic geometric configurations are provided with deliberate deviationsfrom the basic configuration such as the previously describedprojections and 16 and recesses 22. The gaps 23 and 24 also definedeliberate sharp deviations which enhance surface regeneration. Stillother deliberate deviations from the basic geometric configuration maybe in the form of simple square projections such as that shown at 26 ofFIG. 10, one of the projections 26 being inside the loop and the otherprojection 26 being on the external surface of the loop. Furtherdeviations may be provided in the form of sharply defined V-shapednotches or recesses 27 illustrated in FIG. 10, which recesses have walls28 extending perpendicular to loop surface 29.

In FIGS. 11 and 12 of the drawing there is disclosed a furtherembodiment of the present invention. In this respect, a loop l0e ofapacking unit is illustrated which includes inner and outer peripheralsurfaces 30 and 31 and side surfaces 32. All of these surfaces haveopposite ends which meet in area 33 which designates the juncturebetween adjacent loops interconnected in the manner of the loops ofFIG. 1. It will be understood, however, that the loops may be continuousas in the unit illustrated in FIG. 5, for example. Each of the surfaces30, 31 and 32 defines a flow path for liquid. At least one of thesesurfaces is provided with a deliberate abrupt deviation intermediate theopposite ends thereof, and in this embodiment the deviation is a sharplydefined offset formed by offsetting portions of the filament of the looprelative to one another either longitudinally of the loop axis, radiallyof the loop axis or longitudinally and radially of the loop axis. Moreparticularly, portions of the filament of the loop at the top of theloop, for example, may be longitudinally offset to define abruptdeviations along surfaces 32, which abrupt deviations include wall means34 and 35 extending substantially perpendicular to the correspondingsurface 32. Similarly, portions of the bottom ofthe loop may belongitudinally offset relative to the loop axis to define abruptdeviations having wall means 36 and 37 extending substantiallyperpendicular to surfaces 32. It will be noted that the lower portionsof the loop are offset longitudinally in opposite directions from thedirection of offset of the top portions of the loop. It will beappreciated, however, that the offsets could be in the same directionlongitudinally of the axis and could be provided at any desired locationalong the length of the filament.

The outer area of the filament of loop We is illustrated as havingportions offset radially of the loop axis to define abrupt deviations ininner and outer surfaces .30 and 31 of the loop. These deviationsinclude wall means 38 and 39 extending substantially perpendicular toinner and outer surfaces 30 and 31 of the loop, re spectively. It willbe noted that the offset of the outer portion of the loop is less thanthe full thickness of the filament, while the offsets at the top andbottom of the loop are illustrated as being the full thickness of thefilament material. This is illustrative of the fact that the offset canbe to any desired degree relative to the thickness of the loop filament.Moreover, a given offset can be both longitudinal and radial relative tothe loop axis. Thus, loop portions 40 and 41 might well belongitudinally offset as well as radially offset in the mannerillustrated. Similarly, the upper and lower loop offsets could well beradially offset together with the longitudinal offset illustrated.

Abrupt deviations in the form of sharply defined offsets provide thedesirable hold up points on a packing unit provided therewith andfurther advantageously provide interruptions in the otherwise smoothsurface which serve to reduce interlocking of adjacent units.

It will be appreciated that the loop 10:: can also be provided withprojections or recesses of the character described hereinbefore and thatthe other packing unit embodiments described herein can be provided withoffsets of the character herein described. Further, in those embodimentsof packing units wherein an annular ring is disposed about the outerperiphery of the loops, about the inner periphery of the loops, or isotherwise associated with the loops, such ring may advantageously beprovided with offset portions of the character described in conjunctionwith this embodiment.

The invention has been described with reference to the preferredembodiments. Obviously, modifications and alterations will occur toothers upon the reading and understand of this specification. It is myintention to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalencethereof.

What is claimed is:

1. A packing material unit for liquid-gas contact apparatus, said unitincluding a plurality of elongated filament portions of narrow width andthickness relative to the length thereof, said filament portions havingopposite ends and having narrow elongated surfaces between said oppositeends defining flow paths for liquid, at least one of said surfaceshaving an abrupt deviation intermediate the opposite ends thereof andtransverse to the direction therebetween, said deviation includingsurface at spaced locations in said direction, whereby said deviationabruptly interrupts the contour of said one surface to define a hold-uppoint by which liquid on said one surface is displaced therefrom.

2. A packing unit as in claim 1, in which said deviation is a sharplydefined recess in said one surface.

3. A packing unit as in claim 1, in which said deviation is a sharplydefined projection extending outwardly from said one surface. I k

4. A packing unit as in claim 3, in which said filament is substantiallysquare in cross-section and said projection has a width greater than thewidth of said one surface.

5. A packing unit as in claim 1, wherein a second of said surfaces ofsaid filament portions is provided with at least one abrupt deviation,said one deviation including surface means continuous with said secondsurface in the direction between the opposite ends of said secondsurface and having opposite sides substantially perpendicular to saidsecond surface and intersecting said second surface at spaced locationsin said direction, whereby said one deviation abruptly interrupts thecontour of said second surface to define a hold-up point by which liquidon said second surface is displaced therefrom.

6. A packing unit as in claim 8, in which said abrupt deviation and saidone abrupt deviation are sharply defined projections extending outwardlyfrom the corresponding one of said one and second surfaces.

7. A packing unit as in claim 5, in which said abrupt deviation and saidone abrupt deviation are sharply defined recesses.

8. A packing unit as in claim 5, in which one of said abrupt deviationand said one abrupt deviation is a sharply defined projection and theother is a sharply defined recess.

9. A packing material unit for liquid-gas contact apparatus comprising aplurality of elongated filament portions each substantially in the formof a loop, said loops being disposed in a circular pattern about anaxis, each of said loops having narrow inner and outer peripheralsurfaces defining flow paths for liquid, at least one of said surfacesof each of said loops having at least 10. A packing unit as in claim 9,wherein said deviation in said one surface is a sharply defined recess.

one abrupt deviation including surface means continu- 11. A packing unitas in claim 9, wherein said abrupt deviation is an annular filamentextending about said axis and being interconnected with at least one ofsaid loops.

12. A packing unit as in claim 9, wherein said deviation in said onesurface is a sharply defined porjection extending outwardly from saidone surface.

13. A packing unit as in claim 12, and a filament ring interconnectedwith the outer surface of at least one of I said loops.

14. A packing unit as in claim 12, wherein the other of said surfaces ofeach-of said loopshas at least one abrupt deviation therein, said oneabrupt deviation including surface means peripherally continuous withsaid other surface and having opposite sides substantially perpendicularto said other surface and intersecting said other surface atperipherally spaced locations therealong, whereby said one deviationabruptly interrupts the contour of said other surface.

15. A packing unit as in claim 14, wherein said deviation in said otherof said surfaces is a sharply defined projection extending outwardlyfrom said other surface.

16. A packing material unit for liquid-gas contact apparatus comprisinga plurality of elongated filament portions each substantially in theform of a loop, said loops being disposed in a circular pattern about anaxis and having inner ends extending generally toward said axis andinterconnected, whereby said loops together resemble a torus, each ofsaid loops having narrow inner and outer peripheral surfaces definingflow paths for liquid, said inner and outer surfaces of at least one ofsaid loops each having at least one abrupt deviation including surfacemeans continuous with the corresponding one of said inner and outersurfaces in the peripheral direction thereof and having opposite sidesextending substantially perpendicular to the corresponding surface andintersecting said corresponding surface at peripherally spaced locationstherealong, whereby said deviation abruptly interrupts the contour ofsaid corresponding surface to define a holdup point by which liquidflowing on said corresponding surface is displaced therefrom.

17. A packing unit as in claim 17, wherein said deviations on said innerand outer surfaces are sharply defined projections extending outwardlyfrom the corresponding one of said inner and outer surfaces.

18. A packing unit as in claim 17, wherein said projections aregenerally parallel to said axis.

19. A packing unit as in claim 18, and a filament ring interconnectedwith the outer surfaces of at least one of said loops.

1. A packing material unit for liquid-gas contact apparatus, said unitincluding a plurality of elongated filament portions of narrow width andthickness relative to the length thereof, said filament portions havingopposite ends and having narrow elongated surfaces between said oppositeends defining flow paths for liquid, at least one of said surfaceshaving an abrupt deviation intermediate the opposite ends thereof andtransverse to the direction therebetween, said deviation includingsurface means continuous with said one surface in said direction andhaving opposite sides substantially perpendicular to said one surfaceand intersecting said one surface at spaced locations in said direction,whereby said deviation abruptly interrupts the contour of said onesurface to define a hold-up point by which liquid on said one surface isdisplaced therefrom.
 2. A packing unit as in claim 1, in which saiddeviation is a sharply defined recess in said one surface.
 3. A packingunit as in claim 1, in which said deviation is a sharply definedprojection extending outwardly from said one surface.
 4. A packing unitas in claim 3, in which said filament is substantially square incross-section and said projection has a width greater than the width ofsaid one surface.
 5. A packing unit as in claim 1, wherein a second ofsaid surfaces of said filament portions is provided with at least oneabrupt deviation, said one deviation including surface means continuouswith said second surface in the direction between the opposite ends ofsaid second surface and having opposite sides substantiallyperpendicular to said second surface and intersecting said secondsurface at spaced locations in said direction, whereby said onedeviation abruptly interrupts the contour of said second surface todefine a hold-up point by which liquid on said second surface isdisplaced therefrom.
 6. A packing unit as in claim 8, in which saidabrupt deviation and said one abrupt deviation are sharply definedprojections extending outwardly from the corresponding one of said oneand second surfaces.
 7. A packing unit as in claim 5, in which saidabrupt deviation and said one abrupt deviation are sharply definedrecesses.
 8. A packing unit as in claim 5, in which one of said abruptdeviation and said one abrupt deviation is a sharply defined projectionand the other is a sharply defined recess.
 9. A packing material unitfor liquid-gas contact apparatus comprising a plurality of elongatedfilament portions each substantially in the form of a loop, said loopsbeing disposed in a circular pattern about an axis, each of said loopshaving narrow inner and outer peripheral surfaces defining flow pathsfor liquid, at least one of said surfaces of each of said loops havingat least one abrupt deviation includIng surface means continuous withsaid one surface in the peripheral direction thereof and having oppositesides substantially perpendicular to said one surface and intersectingsaid one surface at peripherally spaced locations therealong, wherebysaid deviation abruptly interrupts the contour of said one surface todefine a hold-up point by which liquid flowing on said one surface isdisplaced therefrom.
 10. A packing unit as in claim 9, wherein saiddeviation in said one surface is a sharply defined recess.
 11. A packingunit as in claim 9, wherein said abrupt deviation is an annular filamentextending about said axis and being interconnected with at least one ofsaid loops.
 12. A packing unit as in claim 9, wherein said deviation insaid one surface is a sharply defined porjection extending outwardlyfrom said one surface.
 13. A packing unit as in claim 12, and a filamentring interconnected with the outer surface of at least one of saidloops.
 14. A packing unit as in claim 12, wherein the other of saidsurfaces of each of said loops has at least one abrupt deviationtherein, said one abrupt deviation including surface means peripherallycontinuous with said other surface and having opposite sidessubstantially perpendicular to said other surface and intersecting saidother surface at peripherally spaced locations therealong, whereby saidone deviation abruptly interrupts the contour of said other surface. 15.A packing unit as in claim 14, wherein said deviation in said other ofsaid surfaces is a sharply defined projection extending outwardly fromsaid other surface.
 16. A packing material unit for liquid-gas contactapparatus comprising a plurality of elongated filament portions eachsubstantially in the form of a loop, said loops being disposed in acircular pattern about an axis and having inner ends extending generallytoward said axis and interconnected, whereby said loops togetherresemble a torus, each of said loops having narrow inner and outerperipheral surfaces defining flow paths for liquid, said inner and outersurfaces of at least one of said loops each having at least one abruptdeviation including surface means continuous with the corresponding oneof said inner and outer surfaces in the peripheral direction thereof andhaving opposite sides extending substantially perpendicular to thecorresponding surface and intersecting said corresponding surface atperipherally spaced locations therealong, whereby said deviationabruptly interrupts the contour of said corresponding surface to definea holdup point by which liquid flowing on said corresponding surface isdisplaced therefrom.
 17. A packing unit as in claim 17, wherein saiddeviations on said inner and outer surfaces are sharply definedprojections extending outwardly from the corresponding one of said innerand outer surfaces.
 18. A packing unit as in claim 17, wherein saidprojections are generally parallel to said axis.
 19. A packing unit asin claim 18, and a filament ring interconnected with the outer surfacesof at least one of said loops.